Plain English Summary
Background and study aims
The rates of childhood overweight (OW) and obesity (OB) significantly increased in the past decades. The prevalence of children with both OW and OB (OW/OB children) in Portugal is one of the highest in the European Union and the OECD area. A comprehensive approach to prevent and treat childhood OW and OB is needed. Since parents have a crucial role in children's diet and physical activity, interventions should include the family's lifestyle and focus on parenting practices. Programs targeting parents by increasing parents' awareness and responsibility in providing environments that lead children to healthy behaviours are imperative in the treatment of childhood OW and OB. The aim of this study is to evaluate the effectivess of Group Lifestyle Triple P (GLTP) in a Portuguese sample of parents of OW/OB children. This is particularly relevant as, to date, there are no such structured interventions available in Portugal.
Who can participate?
Parents of OW/OB children, aged 5 to 10, currently being followed at the paediatrics appointment at the Nutrition Unit of the Paediatric Department (NUPD) of Porto University Central Hospital (Centro Materno-Infantil do Norte, CMIN).
What does the study involve?
Participants will be randomly allocated to the intervention and control groups. The intervention group receives treatment-as-usual (TAU) along with Group Lifestyle Triple P (GLTP), whereas the control group receives only TAU. TAU includes quarterly structured medical appointments delivered by paediatricians, following the guidelines defined by the ESPGHAN Committee on Nutrition, encouraging behavioural change to facilitate consistent and long-term follow-through. GLTP is the only evidence-based program that teaches parents of children with OW (not only with OB) to use positive parenting to promote a healthy lifestyle in their families, through healthy eating and physical activity. It stems from the Triple P - Positive Parenting Program and is delivered in a 14-session intervention over 17 weeks. It aims to decrease the child's weight and weight-related problem behaviour by increasing parents' self-efficacy in managing the child's behaviour and by reducing the use of ineffective parenting practices. Participants take part in three assessment time points at the start of the study and 4 and 10 months after. The following are measured: the child’s body measurements, body composition, dietary behaviour and physical activity levels, behaviour problems and quality of life; the parents' psychological symptoms, parents’ perception of child's weight-related problem behaviour and self-efficacy in managing those problems, overall parenting practices, specific parenting practices regarding feeding and physical activity, and parents’ perception of change and satisfaction following GLTP intervention.
What are the possible benefits and risks of participating?
Participants have the opportunity to receive the GLTP intervention and with that learn strategies to deal with their child’s weight-related problem behaviour effectively, increasing their self-efficacy in managing their child's behaviour, and the use of effective parenting practices. After completing all the assessment time points, participants of the control group will have the opportunity to receive the GLTP intervention. All the participants receive a gift card (€30) as compensation for their travel expenses to participate in the assessment time points. Participants from both groups who receive the GLTP also receive all the materials needed for program implementation. No risks are foreseen for participants.
Where is the study run from?
University of Porto (Portugal)
When is the study starting and how long is it expected to run for?
July 2018 to December 2021
Who is funding the study?
Fundação para a Ciência e a Tecnologia (Portugal)
Who is the main contact?
Prof. Orlanda Cruz
Prof Orlanda Cruz
Faculty of Psychology and Education Science at the University of Porto
Rua Alfredo Allen
Dr Catarina Canário
Faculty of Psychology and Education Science at the University of Porto
Rua Alfredo Allen
A randomised control trial comparing treatment-as-usual and Group LifeStyle Triple P with treatment-as-usual only to evaluate the efficacy of Group LifeStyle Triple P in a sample of parents of overweight/obese children aged 5 to 10: short and long-term (4 and 10 months after baseline) effects on child’s anthropometric measures, body composition, dietary behaviour and physical activity levels, behaviour problems and quality of life; parents' psychological symptoms, perception of child weight-related problem behaviour and self-efficacy in managing those problems, overall parenting practices, specific parenting practices regarding feeding and physical activity, and perception of change
Group Lifestyle Triple P improves the outcomes of the clinical intervention provided to overweight/obese children followed at the Nutrition Unit of the Paediatric Department of the Porto University Central Hospital, in Portugal.
1. Approved 06/10/2016, Ethics Committee of the Faculty of Psychology and Education Science at the University of Porto (Rua Alfredo Allen, s/n, 4200-135 Porto, Portugal; +351 (0)220 400 647; firstname.lastname@example.org), ref: 13-10/2016
2. Approved 25/09/2019, Board of Porto University Central Hospital (Largo Professor Abel Salazar, s/n, 4099-001 Porto, Portugal; +351 (0)222 077 500; email@example.com), ref: 2019.020(017-DEFI/018-CE)
3. Approved 06/02/2019, Data Protection Unit of the University of Porto (Praça Gomes Teixeira, 4099-002 Porto, Portugal; +351 (0)220 408 000; firstname.lastname@example.org), ref: 2018091915006258
Single-centre interventional randomized controlled trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet
Positive parenting intervention in parents of overweight and obese children aged 5 to 10
Recruited participants will complete the baseline assessment and will then be randomly assigned to the two conditions, Group Lifestyle Triple P (GLTP) intervention along with clinical treatment as usual (intervention condition), or solely treatment as usual (control condition). The randomisation process takes place after the baseline assessment and is performed by an independent researcher not directly involved in data collection nor intervention delivery, using a list of computer-generated random numbers. Outcome assessors are not aware whether the participant received or not GLTP intervention. Each of the conditions (intervention and control) will include eight groups of 20 parents.
The intervention condition includes the implementation of the program Group Lifestyle Triple P (GLTP), along with Treatment-As-Usual (TAU). GLTP is a cognitively behavioural intervention aimed at reducing children's risk of chronic weight problems by increasing parents' skills and confidence in managing children's weight-related behaviour. The program targets parents of overweight or obese children aged 5 to 10 years and consists of a 14-session intervention, where parents receive ten 90-minute group sessions and four 20-minute individual sessions. The program is delivered by two accredited practitioners (research team members) at the Faculty of Psychology and Education Science at the University of Porto. TAU consists of structured medical appointments provided by two paediatricians (research team members) in a quarterly frequency at the Nutrition Unit of the Paediatric Department of the Porto University Central Hospital, targeting the promotion of healthy eating habits and physical activity, and the reduction of risk/severity for obesity-related diseases. These medical appointments follow the guidelines defined by the ESPGHAN Committee on Nutrition, encouraging behavioural change to facilitate consistent and long-term follow-through.
The control condition solely receives TAU.
Participants will take part in three assessment time points, at baseline, and 4 and 10 months following baseline.
Primary outcome measure
The study includes three assessment time points for both intervention and control condition at baseline, 4 and 10 months after baseline. The following primary outcomes will be assessed at each timepoint:
1. Child’s anthropometric measures including height, using a SECA stadiometer, weight, using an Inbody 270 scale, and waist and arm circumferences using a SECA measuring tape
2. Child's body composition, body fat percentage and lean body mass percentage, evaluated using an Inbody 270 scale
3. Child's dietary behaviour, obtained by parents’ report on a three-day food intake diary and by parent’s report on child’s intake frequency for specific foods and beverages
4. Child’s physical activity level, obtained by each child wearing a wGT3X-BT Actigraph Accelerometer for 5 days
Secondary outcome measures
The study includes three assessment time points for both intervention and control condition at baseline, 4 and 10 months after baseline. The following secondary outcomes will be assessed at each timepoint:
1. Parents' perception of child's weight-related problem behaviour and self-efficacy in managing those problems, assessed using the Lifestyle Behaviour Checklist (LBC)
2. Parents’ comprehensive feeding practices, assessed using the Comprehensive Feeding Practices Questionnaire (CFPQ)
3. Physical activity parenting practices, assessed using the Physical Activity Parenting Practices (PAPP) questionnaire
4. Parenting styles and practices, assessed using the Alabama Parenting Questionnaire (APQ) and the Parenting Scale (PS)
5. Parents’ treatment self-regulation, assessed using the Treatment Self-Regulation Questionnaire (TSRQ)
6. Parents’ agreement or conflict on parenting practices, assessed using the Parent Problem Checklist (PPC)
7. Parents' perception of the child's quality of life, assessed using the EQ-5D-Y and the Kidscreen
8. Parents' perception of the child’s difficulties and strengths, assessed using the Strengths and Difficulties Questionnaire (SDQ)
9. Parents' recall on parents and child healthcare utilisation and productivity losses assessed using a questionnaire adapted from the TiC-P
The following data will be collected at baseline:
1. Family sociodemographic characteristics collected using a questionnaire
2. Parents' anxiety, depression and stress, assessed using the Depression, Anxiety and Stress Scales (DASS-21)
Participants of the intervention condition will also provide information on the following:
1. Helpful aspects of the intervention, assessed using an adapted version of the Helpful Aspects of Therapy (HAT) interview, at the middle and the end of GLTP delivery
2. Perception of family lifestyle changes, assessed using an interview developed for this purpose, at the end of GLTP delivery
3. Perception of satisfaction with the intervention, assessed using the Triple P Client Satisfaction Questionnaire-Revised (CSQ), at the end of GLTP delivery
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
Mothers and/or fathers of overweight and obese children (BMI for age >+1SD and BMI for age >+2SD according to the WHO Growth Reference 5-19 years ) aged 5 to 10 years old, recruited at the Nutrition Unit of the Pediatric Department (NUPD) of the Porto University Central Hospital (Centro Materno-Infantil do Norte, CMIN)
Target number of participants
Participant exclusion criteria
1. Parents not being able to commit to 6 months of regular contacts
2. Not being willing to make changes in their family's lifestyle
3. Presently participating in a program targeting childhood overweight and obesity
4. Parent of an overweight/obese child diagnosed with endocrine disease-causing overweight or obesity, or diagnosed with cognitive, motor or development delays, or with physical limitations, or currently under medication known to cause overweight or obesity
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
University of Porto
Faculty of Psychology and Education Science Rua Alfredo Allen
Fundação para a Ciência e a Tecnologia
Portuguese Science and Technology Foundation, Foundation for Science and Technology, FCT
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
The study protocol is currently being prepared and will be available when published.
Different dissemination outcomes are planned according to the target population, following the Open Science guidelines (European Commission).
For researchers and the scientific community, expected scientific outputs include the submission of six papers in indexed scientific journals, at least two of which in Open Access International Journals.
Regarding Open Research Data, access to datasets will be provided after rigorously screening the datasets and removing every data that have the potential to jeopardise participants' anonymity and data confidentiality. Thus, the research's partial datasets will be uploaded into Open Research Data Repositories after undergoing a process of data curation.
Regarding Open Scholarly Communication, different actions are proposed.
Aiming at researchers and the scientific community: the study's results will be presented in National and International Conferences.
Aiming at specified (policymakers and stakeholders), and general audience, a seminar regarding the presentation of the results will be organised at the University of Porto.
For practitioners, a workshop focused on the effectiveness and dissemination of the program will be held. The results of this workshop will be compiled and fed back to professionals through the project website.
For parents, flyers and posters informing about Group Lifestyle Triple P as an available resource will be delivered in schools, primary health care centres, and other community centres where parents are often present and search for advice on child-rearing and health issues.
IPD sharing statement
The datasets generated during and/or analysed during the current study will be stored in a publically available repository. Data will be made available on the Open Science Framework platform, on the website https://osf.io/g23fp/?view_only=b55d11b1126a474a9ccc11863e461af9, data to be shared regards primary and secondary outcomes evaluated at baseline, 4 and 10 months after, for participants in both conditions. Data will be available indeterminately at the end of the study, after results publication. Participants give their informed consent regarding data sharing. From ethical and data protection points of view, the research team entitles participants to the right of consulting, rectifying or deleting their personal data until the last assessment time point of the study, from that point onwards data are anonymised. Data from participants who do not consent to data sharing will not be included on the raw data datasets to be shared among the scientific community. The curated and anonymised datasets will be available for download and will have a reference and URL, for those who use them to be able to cite them. Also, the manuscripts published on the results of the current study will include anonymised datasets as supplementary materials, in line with the open science guidelines to foster results reproducibility.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)